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Old 20-07-2004, 02:07 AM
Greg G.
 
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Default Dual T-8 Reflector Design - FREE PLAN


Greetings,

Folks, from what I've seen, most commercially sold reflectors are
generally a joke designed to separate you from $25-$50.

A flat topped reflector with improperly designed side wings does
little to no good, regardless of the inflated price tag or shininess
of the material it is constructed of - Caveat Emptor!

For those who might be interest in building their own reflectors, I am
offering this design based on dual T-8 (1") fluorescent bulbs.

Note that the overall width is 5.125" - something to keep in mind when
trying to stuff 6 tubes into a hood. ;-) This width is optimum for
these tube diameters, any smaller compromises the efficiency by
increasing tube restrike.

Distance of the tube from the reflector is also fairly critical.

This reflector is designed for T-8 bulbs, but due to the dual tube
design, some restrike (~12%) is unavoidable.

Anyone wishing to build a single tube T-8 reflector needs only to cut
vertically at the tube centerlines and rejoin the 2 remaining parts.
This is a better arrangement, as tube restrike is reduced to 0%.

Note that the plan grid is minor 1/8" and major 1". This should make
it easy to replicate at home.

Flat pure white paint is a good choice for a final coating, although
mirror polished aluminum is slightly better.

You don't have to build these out of sheet metal, although metal
roofing flashing would work, and is light enough to work without a
metal brake. Use your imagination! Printers Polycore covered with
HVAC aluminum tape would work, as would painted tempered hardboard.
Anything that will withstand 120dF temperatures and some UV exposure
could be fashioned... Just don't set your house on fire! Leave room
for air flow at the endcaps of the tubes for cooling.

Use an electronic ballast!
Tie both pins together at both ends of the tubes!
They offer lower heat, longer bulb life, lower operating costs, and
the GE UltraMAX offers anti-spiraling and ARC protection circuitry.
(CC rating).

Sylvania Quicktronic and GE UltraMAX ballasts work great, and are
designed for continuous use, multiple bulb configurations, and are
reasonably priced:

2 tube T-8 - $19.00
4 tube T-8 - $27.00

Available at Home Despot and Lowes.


Plan: (32kb)
http://www.thevideodoc.com/images/T-8DualReflector.jpg


Short Video of photon reflection: (1400kb)
http://www.thevideodoc.com/media/T-8DualReflector.mpg

Good Luck,


Greg G.